Jojiah vavabseur



.UNITED STATES PATENT OFFICE.

JOSIAH VA'VASSEUR, OF,BEARLANE, SUTHWARK, COUNTY OF SURREY,

. ENGLAND.

ORDNANCE.

` seniors-:carton forming pm of Letten' :Patent No. 277,634, dated my 15, 1883.

Application died Jennery 3. i583. (No model.) Patented ln England ovember 22, 1882, No. 5,559, and in France December 9, 1882.

T0 all whom #may concern: j

Be it known that I, J Osma VAvAssnUB, a subject of the Queen of Great Britain, and residing'at Bear Lane, Southwark, in the county of Surrey, England, haveinvented certain new and useful Improvements in Ordnance, (for which I have madevapplication for Letters Patent in-Great BtaimNo. 5,559-,dd'te7'November 22, 1882, and in France, Ng-140,283, dated December 9, 1882,) -of whiehrthe following' is aspecitlcation'.

This invention has for its objectimprovem'ent'sin ordnance, and relates especially to- ,devices for'obtaning greater strength longi- .lar rooves in thetubesaml providingehannels lea ing to 'them from the' outside, by which' the grooves have been iiiled with melted. mtal.

My improved method consists in cutting a' coarse screw grooveon the'ex'terior of the inner piece or tube at 'the partwhere it is dey sired to coupieit to the outer piece, and' to eut an exactly'correspoudin'g groove in the bore ofthe outer piece, so' that when the two pieces are shrunk or fitted together there will remainA a-spirally-formed-recess, by preference square Aor rectangular in section, linto which I pass a spirally-formed bar ofsteel or other metal of corresponding section,to tit as closelyas possible into the space thus left for it. The two tubes will thus be longitudinally-coupled together vby. the spiral bar, which must be sheared or deformed before one can slide on the other to any extent likely to endanger Athe structure. -I prefer making the thread in such a direction with respectto the riiing of the tube that any tendency to move the tube ou its axis will ten'd to screw the tube farther into its jacket or the piece to which it is coupled.

lThe annexed drawing is a longitudinal seotion of two portions of a gun united in accordance with my invention.

Asthe' outerand B the inner part. Within A a spiral groove is cut, and a like groove .is cut upon the exterior of B. The outer part is then shrunk uponithe inner in the usual way, but with care that the grooves shall coincide and form a spiral passage. -A spiraily-iormed bar of steel or other suitable metal, C, of a size just t be ableto pass, is then inserted by screwing into the passage.

I Claimt l As an improvement iii ordnance, the combination of the tubes A and B, provided with'. v

the coinciding spiral grooves, end aspiraljbar secured in the grooves, substantially as and for the purpose hereinbefore set forth.

l Josue irtvaseisun,` Witnesses'z.

E.DON,N, '(LlilWAmas,l Both of Bear Lang, Southwark, London. 

